[mythtv-users] Thinking of moving on from MythTV :-( Any suggestions? (for the UK)

[Simon Hobson]

Mike Perkins <mikep at randomtraveller.org.uk> wrote:

> A point about grouped aerials. They are likely to become less useful in the future as multiplexes are moved around.

Yes and no, sort of !
Up here in Winter Hill land, I see there is talk of us moving from the top end (Gp C/D) down to the bottom (Gp A) - but that's a few year off yet, and still in "will it, won't it" land depending on what happens with selling off spectrum for mobile phones. For now I'm inclined to go with a grouped Yagi and accept that I'll probably have to replace it in a few years. I have a Log36 in the loft at the moment, and even allowing for it being in the loft, it's performance is "disappointing" - can't get a usable signal from Winter Hill, "mostly OK" from Lancaster. At some point I'll get a grouped yagi and see how that compares.


Gary Buhrmaster <gary.buhrmaster at gmail.com> wrote:

> Your typical physicist or EE understands the technology,
> but there is a reason that your typically installer does
> not have that degree (and it involves your willingness to
> pay their usual and customary rates for that knowledge).
> 
> Anyone can hang out a shingle saying "experienced
> TV antenna installer".  Real knowledge requires a bit
> more (and very expensive) learning and the tools to
> do the validation(*).  "Looks good to me" is not the
> equivalent of a spectrum analysis report (old adage,
> "You get what you pay for").

Yep - skill and knowledge "varies widely" would be a polite way of putting it. Sadly the average person doesn't know enough to know wheich end of the spectrum they are dealing with. At one end you'll get a suitable aerial correctly fitted and cabled; at the other end you'll get a bacofoil wideband which will only be correctly connected by luck (if you are lucky).
When I took the old aerial down at my parents a few years ago, I found a hole drilling in the top of the terminal box lid. As the lid was on top I might suspect a charlatan of having put it there so as to make things fail - not so quickly as to be warranty work, but long enough that you could charge for "repairs".

> (**) I used to recommend a end-to-end validation of
> (network) cabling in the RFP.  I a lot of contractors
> dropped out when they understood that that required
> equipment (such as the Fluke DTX-1800) that they
> not only had to purchase, but be trained to use.  Some
> of the "cable monkeys" they used for installations were
> not quite ready for that step.

Ha ha, I know what you mean there. I actually possess my own personal kit that I picked up really cheap a few years ago in a new year sale by a test equipment dealer. Sadly it's only a DSP-100 (only Cat5) but that's 100% better than the "no testing" you and I are both familiar with. I use it mostly for troubleshooting - the amount of time saved by knowing which end is open circuit ...



Mike Perkins <mikep at randomtraveller.org.uk> wrote:

> Second, you say that after a reboot everything is fine and then begins to go off after a while. That suggests to me a cooling problem. The chips in the tuners are fine when fresh but degrade once they have been used for a while. Is the ventilation around your box adequeate?
> 
> Another related problem may be the gradual failure of components in your tuner chain. Things like the chips, yes, but also caps and even power dongles if your tuners use them. Replacing a tuner may be one solution, though this involves spending money, of course. It would be preferable to locate the source of the problem before spending but sometimes that isn't possible.
> 
> If you have a spare box I would suggest making up a basic standalone system using one of the tuners and using that to test. That way you can see if the tuner is at fault or some other part of the chain. Swap tuners until you see something that gives you an answer.

I also wonder if there could be a software issue, such as a driver that "accumulates cruft" over time and gets "less reliable". Not sure why that would work in a mux specific way though. If a simple reboot (not power off/on) cures things, then I'm not sure how cooling issues would be fixed by that.